Abietate modified polysulfide polymers

ABSTRACT

A POLYSULFIDE POLYMER IS REACTED WITH ABIETIC ACID AND IS EFFECTIVE AS AN ADHESIVE ADDITIVE FOR A POLYSULFIDE POLYMER-BASED COMPOSITION USED AS SEALANTS OT BONDING AGENTS ON VARIOUS SUBSTRATES SUCH AS GLASS OR ALUMINUM.

United States Patent O 3,813,368 ABIETATE MODIFIED POLYSULFIDE POLYMERSJos L. Villa, Heightstown, N..I., assignor to Thiokol ChemicalCorporation, Bristol, Pa. No Drawing. Filed May 12, 1972, Ser. No.252,646 Int. Cl. C08g 23/00 US. Cl. 260-79 2 Claims ABSTRACT OF THEDISCLOSURE A polysulfide polymer is reacted with abietic acid and iseffective as an adhesive additive for a polysulfide po1ymer-basedcomposition used as sealants or bonding agents on various substratessuch as glass or aluminum.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to improved liquid polysulfide polymer based adhesivecompositions containing novel adhesive additives. More particularly,this invention relates to improved liquid polysulfide polymer basedadhesive compositions containing novel adhesive additives prepared bymodifying polysulfide and polyester polymers with abietic acid andpolysulfide polymers with epoxy groups.

Description of the prior art Curable, liquid polysulfide polymer basedsealant and caulking compositions have long known in the art. They arebased on curable, liquid, mercaptan terminated polysulfide polymers. Ihestructure and preparation of these polythiopolymercaptan polymers aredisclosed in US. 2,466,963. These liquid, mercaptan terminated polymersare used extensively in sealant and caulking compositions, especially inthe building, automotive, and marine industries; for castings, e.g.,solid rocket propellants; for leather and textile impregnating agents;for adhesives, coatings, etc. Because of the wide range of applicationsin which these polysulfide polymer based sealing and caulkingcompositions are used, they must be capable of bonding to varioussubstrates, e.g., metal, aluminum, glass, concrete, wood, etc. However,the adhesive qualities of polysulfide polymers are such as to usuallyrequire the use of an adhesive additive in the polysulfide polymer basedsealant composition in order to insure adequate bonding of the curedsealant to the substrate.

Adhesive additives of the prior art such as those of a phenolic natureprovided only a polar, rather than a chemical, type bonding of the curedsealant to the substrate. 'Ihus, sealant compositions containingphenolic type adhesive additives were found to be susceptible to attackby polar solvents such as water. The polar solvent tended to break downthe polar bond thereby impairing the utility of the sealant composition.More recently, as disclosed in US. Pats. 3,297,473; 3,312,669, and3,328,- 451, certain organo-silanes e.g. (mercapto alkyl amino alkylalkoxyl silanes) have been proposed to overcome these problems. However,while the organo-silane adhesive additives have been found to protectthe sealant composition bonds from attack by polar solvents, they dohave certain disadvantages. Thus, the organo-silane adhesive additivesare economically costly, somewhat deficient in storage stability, andexhibit erratic adhesion results with certain substrates, such asconcrete.

The object of the present invention, therefore, is to provide a novelliquid polysulfide polymer based caulking or sealant composition whichwill allow for the attainment of a strong and lasting bonding of thesealant to the substrates to be treated therewith.

Another object of the present invention is to provide "ice a novelliquid polysulfide polymer based caulking or sealant compositioncontaining adhesive additives which are less costly, exhibit improvedstorage stability, and which exhibit more reproducible and uniformadhesion characteristics to a Wider range of substrates.

Other objects of the invention will become apparent to those skilled inthe art from a consideration of the following detailed description.

SUMMARY OF THE INVENTION It has now been unexpectedly found that theobjects set forth above can be accomplished by the use of an abietateterminated polysulfide polymer, an abietate terminated polyesterpolymer, or an epoxy terminated polysulfide polymer as an adhesiveadditive for the liquid polysulfide polymer based sealant composition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As indicated previously, thenovel adhesive additives of the present invention are the abietateterminated polysulfide polymers, the abietate terminated polyesterpolymers, and the epoxy terminated polysulfide polymers. Of theseadhesive additives, the abietate terminated polysulfide polymers arepreferred because they exhibit more uniform and reproductible adhesionresults to various substrates when incorporated into a liquidpolysulfide polymer based sealant composition. The abietate terminatedpolyester polymer and epoxy terminated polysulfide polymer adhesiveadditives show increased adhesion to certain substrates. However, it hasbeen found that larger quantities of these latter adhesive additives arerequired to produce increased adhesion results. The useof these adhesiveadditives in the required quantities often results in some retardationof the cure rate of the sealant composition. Moreover, adhesion resultson the abietate terminated polyester polymer and epoxy terminatedpolysulfide polymer adhesive additives have not proven to be as uniformnor as reproducible as the preferred abietate terminated polysulfidepolymer adhesive additive. For that reason, it is recommended that theabietate terminated polyester polymer and epoxy terminated polysulfidepolymer adhesive additives be used at not more than 5 parts by weight ofadditive per parts by weight of liquid polysulfide polymer based on thetotal weight of the sealant composition. Larger quantities of theseadhesive additives may require an adjustment in the amount of curingagents employed.

The abietate terminated polysulfide polymer adhesive additive of thepresent invention may be prepared by reacting a relatively low molecularweight, e.g., 500 to 4000, preferably 500 to 1500, SH terminated liquidpolysulfide polymer (hereinafter referred to as a liquid polythiolpolymer) with abietic acid at temperatures of from C. to 200 C. Thereaction is preferably carried out in a solvent medium and under aninert atmosphere.

The liquid polythiol polymer used as the starting material for reactionwith the abietic acid may include those polythiopolymercaptan polymersas are disclosed in US. Pat. 2,466,963 and which may be represented bythe formula HS(RSS),,RSH where R is a hydrocarbon, oxahydrocarbon orthiahydrocarbon radical such as the ethyl formal radical (-CH CH O--CHO-CH -CH the butyl formal radical cH, cH,-cH, cH,' o

CH -0CH CH CH -CH the ethyl radical and the bntyl ether radical (CH C-H-CH CH O CH -CH CHHH -J and n will vary from about 4 to 23.

A preferred liquid polythiol polymer will have a molecular weight of 500to 4000. A particularly preferred liquid polythiol polymer used in thepractice of the present invention is a liquid polythiol polymercontaining no crosslinking and having a molecular weight of 1000.

While the reaction between the liquid polythiol polymer and abietic acidis not known with exact certitude, it is theorized that the reactionproceeds with inversion of a mercaptan terminal to a hydroxyl terminalfollowed by esterification. The reaction is believed to proceed in thefollowing manner:

heat

wherein n will vary from 4 to 23.

As indicated previously, the reaction product of the liquid polythiolpolymer and abietic acid is believed to be predominantly of the generaltype structure shown above. However, it should be observed here that thereaction product may in fact contain a mixture of chemical structures.Thus, it is likely that in addition to the above sructure, the reactionproduct may contain structures wherein there are abietate terminals atboth ends of the polysulfide polymer chain and in addition may containunreacted liqiud polythiol polymer with SH terminals at both ends of thepolymer chain. The predominant type structure obtained is influenced inlarge measure by the reaction conditions employed. The abietateterminated polysul'fide polymer adhesive may be incorporated into theliquid polysulfide polymer based sealant composition in amounts of from0.5 to 3.5 parts by weight per 100 parts by weight of liquid polysulfidepolymer.

The abietate terminated polyester polymer adhesive additive may beprepared by any of several procedures. For example, a hydroxylterminated liquid polyester polymer of relatively low molecular weighte.g. 500 to 2500, preferably 500 to 1500, may be reacted with abieticacid under an inert atmosphere at temperatures ranging from about 140 C.to 200 C. with or without the presence of a solvent. Alternatively, theindividual components which react to form the hydroxyl-terminated liquidpolyester polymer may be directly admixed with the abietic acid in asuitable mixing apparatus and then reacted to form the abietateterminated polyester polymer used as the adhesive additive in thecompositions of the present invention.

The hydroxyl-terminated liquid polyester polymers which may be reactedwith abietit; acid to form e abietate terminated polyester polymeradhesive additives of the present invention may be virtually any ofthose known to the art. These hydroxyl-terminated liquid polyesterpolymers may be prepared in known manner by reacting diols or polyolswith dicarboxylic or polycarboxylic acids under temperature and pressureconditions known in the art. Typical dicarboxylic acids useful inpreparing the polyesters include oxalic, adipic, azelaic, sebacic,maleic, and fumaric acids and others, as well as mixtures of theseacids. The diols used may include ethylene glycol, diethylene glycols,alkane diols, castor oil and the like. As indicated previously, theliquid polyesters preferably have a molecular weight of 500 to 2500.

Liquid polyester polymers containing sulfur in the polyester moleculeare particularly preferred in the practice of the present inventionsince they are believed to be more compatible with the liquidpolysulfide polymer of the sealant composition. A preferred abietatemodified sulfur containing polyester polymer adhesive additive of thepresent invention may be prepared by mixing and reacting thiodiethyleneglycol, azelaic acid, maleic anhydride, and abietic acid under an inertatmosphere at a temperature of 130 C. to C. The resulting abietateterminated polyester polymer adhesive additive may be incorporated intothe liquid polysulfide polymer based sealant composition in amountsranging from 0.5 to 5.0 parts by weight per 100 parts of liquidpolysulfide polymer. At the higher concentration some retardation of thesealant composition cure rate is observed.

The epoxy modified polysulfide polymers used as adhesive additives inthe compositions of the present invention may be prepared by reacting arelatively low molecular weight e.g. 500 to 4000, preferably 500 to1500, liquid polythiol polymer, such as the liquid polythiol polymerdescribed previously, with a diepoxide such as vinyl cyclohexanediepoxide in a solvent medium in the presence of an acid catalyst. Thechemical reaction between the liquid polythiol polymer and vinylcyclohexane diepoxide is theorized to proceed as follows:

HS-(RS Sh-RSH-l- O HS-(RSS) --RS Gig- OE,

where R is the ethyl formal radical (CH -CH OCI-I 0CH CH and it may varyfrom 4 to 23.

In the above reaction, the epoxy cyclohexane group is reactive underacidic conditions whereas the epoxy ethyl group is reactive under basicconditions. The chemical structure shown above is believed to be thepredominant form of the reaction product. However, it should be observedthat the reaction product very possibly may consist of a mixture ofmaterials with varying structures. Thus, it is possible that thereaction product in addition to the above structure may contain aproduct wherein the polysulfide polymer has an epoxy terminal at bothends of the polymer chain or a portion of the reaction product has SHterminals at both ends of the polymer chain.

A particularly preferred epoxy terminated polysulfide polymer adhesiveadditive of the present invention is prepared by reacting a liquidpolythiol polymer of 1000 molecular weight having no crosslinking withvinyl cyclohexane diepoxide in a solvent medium in the presence of anacid catalyst.

The reaction product of a liquid polythiol polymer and a diepoxide is anepoxy terminated polysulfide resin which can be incorporated into theliquid polysulfide polymer based sealant composition in an amountranging from 0.5 to 5.0 parts by weight of epoxy terminated polysulfideresin per 100 parts by weight of polysulfide polymer. At the higherconcentration of adhesive additive, some retardation of sealantcomposition cure rate is observed.

The liquid polysulfide polymers which form the polymer base of thesealant or caulking compositions with which the novel compounds of thepresent invention are used as adhesive additives are those liquidpolythiopolymercaptan polymers as are disclosed and claimed, as notedabove, in U.S. Pat. 2,466,963. The most preferred of such polymers forthe purposes of making sealant or caulking compositions are those havinga molecular weight of about 500 to 4000.

The liquid polysulfide polymer curing agents which may be used insealant compositions with the novel adhesive additive compounds of thepresent invention include all those materials known to the art as liquidpolysulfide polymer curing agents such as polyepoxy resins, leadperoxide, calcium peroxide, zinc peroxide, lithium peroxide, bariumperoxide, tellurium dioxide and the various chromate salts as aredisclosed in U .S. 2,964,503. In addition, as disclosed in U.S.3,487,052 various other inorganic oxides and peroxides, organicperoxides, permanganates, organo tin compounds, organic nitro compounds,and quinoid compounds can often be advantageously used as curing agentsfor said liquid polysulfide polymers. About 2 to parts by weight of oneor more of such curing agents should be used in such compositions per100 parts by weight of liquid polysulfide polymer being used.

Curable liquid polysulfide polymer based sealant compositions used inconjunction with the adhesive additive compounds of the presentinvention may also contain various types of inert materials commonlyemployed in liquid polysulfide polymer based sealant compositions suchas fillers, plasticizers, pigments, ultraviolet light stabilizers, cureaccelerators, and the like.

The substrates which can be treated with sealant compositions containingthe novel adhesive additives of the present invention include those of awood nature, those of a silicaceous nature such as glass, those of ametallic nature such as aluminum, iron, and steel, and to a limiteddegree concrete.

In order to illustrate further the nature of the present invention, thefollowing examples are submitted. These examples are merely illustrativeof the present invention and are not intended as a limitation upon thescope thereof.

EXAMPLE 1 Preparation of abietate terminated liquid polysulfide polymerresin A 4000 ml. resin kettle equipped with a Barrett trap, athermometer and adapter, an electric stirrer, a gas inlet tube and aFredricks condenser was charged with 2000 grams (2 moles) of a liquidpolythiol polymer of 1000 mol. weight having no crosslinking, 604.88grams (2 moles of abietic acid, and 150 mls. of xylene. The mixture washeated under a nitrogen atmosphere for approximately 1 hour minutes atwhich time the temperature had reached 190 C. and 10 mls. of H 0 hadcollected in the Barret trap. The mixture was then heated forapproximately 2 /2 hours at 190 C. at which time 34 mls. of H 0 hadcollected in the trap. The mixture was heated for an additional 10minutes and the heat then removed. A sample of resinous product wasremoved from the resin kettle and analyzed for SH percentage. SH percentwas would to be 2.7%. The next morning, heat was again applied to themixture for approximately 2 hours at 165 C. An additional 6 /2 mls. of H0 collected in the trap for a total of 41 mls. of H 0 collected andremoved during the reaction. Heat was removed at this time and a sampleof resinous product analyzed for SH percentage. Analysis indicated thatSH percentage was 0.5%. A vacuum was hooked up to the reaction apparatusand the reaction was heated to 70 C. until all of the xylene had beenevaporated. The resinous abietate terminated polysulfide polymer wascollected and the acid number and hydroxyl number determined. Resultswere as follows:

Acid No. 0H No.

About 5.5 pounds of abietate terminated polysulfide polymer resin wasprepared by the above procedure and used as an adhesive addition in theexamples which follow.

EXAMPLES 2-4 Evaluation of the abietate terminated polysulfide polymerresin of Example 1 as an adhesive additive in liquid polysulfide polymerbased sealant compositions In order to determine the effectiveness ofthe abietate terminated polysulfide polymer resin of Example 1 as anadhesive additive, a liquid polysulfide polymer based sealantmasterbatch of the following formulation was prepared using mixingprocedures well known in the sealant art:

Ingredients: Parts by weight LP-32 polysulfide polymer 1 100.0 MultiflexMM (calcium carbonate) 25.0 Icecap R (anhydrous clay) 30.0 Titanox RA 50(titanium dioxide) 10.0

Arocholr 1254 (chlorinated diphenyl) 35.0

200.0 LP-32 polysulfide polymer has essentially the structure S S)2sC2H4O-CH2OC2H4SH with about 0.5% crosslinking and a molecular weightof about 4000.

A control formulation (Example 2) for this evaluation was prepared bycombining the above sealant masterbatch with a lead peroxide curingpaste (described hereinafter). One test formulation (Example 3) wasprepared by combining the sealant masterbatch with the abietateterminated polysulfide polymer resin and a lead peroxide curing paste.An additional test formulation (Example 4) was prepared by combining thesealant masterbatch with the abietate terminated polysulfide polymerresin and a zinc peroxide curing paste (described hereinafter). Thecontrol and test formulations were as follows:

The lead peroxide curing paste shown above is a mixture of lead peroxideand Arochlor 1254 containing 50% PbO Arochlor 1254 is a chlorinateddiphenyl plasticizer. The zinc peroxide curing paste shown above is amixture of zinc peroxide, Arochlor 1254, and amax containing 45.5% ZnO45.5% Arochlor 1254, and 9% amax. Arnax is n-oxy-diethylenebenzothiozole-Z-sulfamide and is used as a cure accelerator.

Peel adhesion strength specimens bonded to glass and aluminum substrateswere prepared from the above formulations. These specimens were exposedto 7 days in air at room temperature, 7 days in an oven at 158 F., and 7days immersion in room temperature water. Peel adhesion valves wereobtained upon removal of the specimens from water immersion while thesamples were still wet using an Instron tester. The results of the peeladhesion tests are shown in Table I.

TABLE I Adhesion peel strength values (p.s.i.)

Substrate Glass Aluminum Example Test 1 Test 2 Test 1 Test 2 NA NA NA NA52 53 28 28 46 53 30 3X 'NA=N0 adhesion.

The control specimens showed complete adhesion failure to both the glassand aluminum substrates.

EXAMPLE 5 Evaluation of the abietate terminated polysulfide polymerresin as an adhesive additive in a liquid polysulfide polymer basedsealant composition utilizing a calcium peroxide curing system In thisexample, the abietate terminated polysulfide polymer resin was combinedwith the polysulfide sealant masterbatch shown below, cured with acalcium peroxide curing paste (described below) and then tested for peeladhesion using the procedure described in Examples 2-4.

Polysulfide sealant masterbatch: Parts by weight LP-32 polysulfidepolymer 100.0

Witcarb RC (precipitated calcium carbonate) 40.0 Cameltex (calciumcarbonate) 25.0 Titanox RA 50 (titanium dioxide) 10.0 Thixcin GR(thixotropic agent) 10.0 Aroclor 1254 (chlorinated diphenyl) 20.0Santicizer 160 (butyl benzylphthalate) 20.0

As indicated previously, the above sealant masterbatch was combined withthe abietate terminated polysulfide polymer resin and a calcium peroxidecuring paste to form the test formulation. The test formulation is shownbelow.

Polysulfide sealant test formulation Ingredients: Parts by weightPolysulfide sealant masterbatch 225.0 Abietate terminated polysulfidepolymer resin 1.0 Calcium peroxide curing paste 37.5

TABLE II Adhesion peel strength values (p.s.i.)

Substrate Glass Aluminum Example Test 1 Test 2 Test 1 Test 2 EXAMPLES6-7 Evaluation of the efiect of the abietate terminated polysulfidepolymer resin on the storage stability of a two package polysulfidepolymer based sealant composition In these examples, the etiect of theabietate terminated polysulfide polymer resin on the storage stabilityof a two package sealant composition was determined by admixing saidresin with the polysulfide sealant masterbatch used in Examples 2-4 andthen aging the admixture in an oven for 7 days at 158 F. A sample of theabove oven aged admixture was then combined with lead peroxide curingpaste to form one test formulation (Example 6) while an additionalsample of the oven aged admixture was combined with zinc peroxide curingpaste to form a second test formulation (Example 7). Specimens of thetest formulations bonded to aluminum and glass substrates were thenprepared for peel adhesion strength tests in accordance with theprocedure described in Examples 2-4. The test specimens were then agedfor 7 days in air at room temperature, 7 days in an oven at 158 F., and7 days immersed in room temperature water.

In essence, this evaluation serves to measure the elfect of hightemperature storage on a two package sealant composition wherein theabietate terminated polysulfide polymer resin is incorporated into theliquid polysulfide polymer based sealant package. Thus, the test is alsoa measure of the storage stability of the resin as an adhesive additive.

The test formulations and peel adhesion values as determined on aInstron tester are shown in Table HI.

TAB LE III Parts by weight Test formulations Ex. No. 6 Ex. No. 7

Polysulfide sealant masterbatch 200 .0 200 .0 Abietate terminatedpolysulfide polymer resin 1.0 1 .0 Lead peroxide curing paste 15 .0 Zincperoxide curing paste 22.0

See the following table:

Adhesion peel strength (115.1.)

Substrate Glas 3 Aluminum Example Test 1 Test 2 Test 1 Test 2 EXAMPLE 8Preparation of abietate terminated polyester resin adhesive additive A1000 ml. resin pot equipped with a Barret trap, a thermometer andadapter, an electric stirrer, a gas inlet tube, and a Fredrickscondenser is charged with 299.20 grams (2.45 moles) of thiodiethyleneglycol, 165.35 grams (.88 moles) of azelaic acid, 86.02 grams (.88moles) of maleic anhydride, and 170.00 grams (.56 moles) of abieticacid. The mixture was heated under a helium atmosphere for about 1 /2hours at temperatures of C. to C., at which time 29 mls. of H 0 hadcollected in the trap. The mixture was permitted to stand overnight. Thenext morning heat was again applied to the reaction mixture and it washeated for 2 hours at which time the temperature was 190 C. and a totalof S5 mls. of H 0 had collected in the trap. At this time, approximately35 mls. of xylene were added to the reaction mixture. The mixture wasthen heated for an additiodnal 6 hours at temperatures ranging from C.to 200 C. at which time a total of approximately 64 mls. of H 0 hadcollected in the trap. At this point, the reaction mixture had beenheated for a total of approximately 8 hours. The reaction mixture wasagain permitted to stand overnight.

The next morning heat was again applied to the reaction mixture and themixture heated for approximately 6 hours at temperatures of 150 C. to175 C. at which time a total of about 66 mls. of H had collected in thetrip. At this time, heat was removed and the reaction mixture allowed tocool to 100 C. A vacuum system was then hooked to the reaction mixtureapparatus and the reaction heated at 150 C. for 2 hours under 7 mm. ofHg pressure to remove any H O or solvent remaining in the resinousproduct. A sample of resin product was analyzed for OH number and acidnumber with the following results: OH number =13.11, acid number=37.40,38.72. A total of 645 grams of abietate terminated polyester resin wereproduced during the reaction.

EXAMPLES 9-12 Evaluation of abietate terminated polyester resin as anadhesive additive in polysulfide sealant formulations In these examples,the abietate terminated polyester resin of Example 7 was evaluated at 1%and levels in the polysulfide sealant masterbatch of Examples 2-4according to the following formulations:

Lead peroxide curing paste--- Zinc peroxide curing paste....

to form the curable sealants 8, 9, 10, and 11. The above sealantcompositions were applied as beads in duplicate to clean unprimed glass,aluminum, and concrete panels and left to cure for 7 days in air at roomtemperature. One set of duplicates was tested for adhesion. The otherset of panels was then immersed in tap water for 7 days at roomtemperature and then tested for adhesion. The adhesion tests consistedof attempting to peel the cured sealant beads from the substrates. Ifthe bead could not be removed without tearing the head, this was notedas a cohesive failure. If the bead peeled oif it was noted as anadhesive failure. If the bead separated during water immersion or ifvirtually no force was required to remove the bead, it was noted ashaving no adhesion (NA). Results of these adhesion tests are shown inTable IV.

10 EXAMPLE 13 Preparation of epoxy terminated polysulfide resin adhesiveadditive A 500 ml. B necked RB flask equipped with an air condenser,thermometer, stirring rod and mixer was charged with 100 mls. ofdioxane, 0.5 grams p-toluene sulfonic acid, 200 grams of liquidpolythiol polymer containing no crosslinking and having a molecularweight of 1000, and 59 grams of vinyl cyclohexane diepoxide. Thereaction was designed to terminate when a 50% reduction of the estimatedSH percent and epoxy group percent of the original reactants wasobtained. The liquid polythiol polymer contained an estimated 6.4% 5Hand the vinyl cyclohexane reactant contained an estimated 34% epoxygroups. The reaction mixture was heated to 50 C. for 6 hours andminutes. At this time, the reaction mixture was heated to reflux at 113C. for 7 hours and 40 minutes. During this period, the reaction mixturewas sampled and analyzed for SH percent and epoxy percent. Analysis ofthese groups showed less than 50% reduction in SH percent and epoxypercent. Accordingly, the mixture was permitted to stand overnight. Onthe next day, heat was again applied to the reaction mixture and it washeated for an additional 6 hours at 111 C. At this point, a sample ofreaction product was analyzed and SH percent was found to equal 3.39%and epoxy percent was found to equal .171%. This indicated anapproximate reduction of 50% in the original SH and epoxy grouppercentages. The reaction mixture was then placed in a rotor vacuumwater aspirator and a hot water bath to evaporate the solvent. Theexperimental procedure yielded 211.2 grams of product. Total heatingtime of the reaction mixture was about 20 hours.

EXAMPLES 14-17 Evaluation of epoxy terminated polysulfide resin as anadhesive additive in a polysulfide sealant composition In theseexamples, the epoxy terminated polysulfide resin of Example 12 wasevaluated in the polysulfide seal-. ant masterbatch of Example 2 at a 1%and 5% level in the following formulations:

TABLE IV Conditions 7 days in air at room temp. 7 days in waterSubstrate Example Percent number additive Curing agent Glass AluminumConcrete Glass Aluminum Concrete 1 PhD: paste.... 0 NA NA 0 A NA 5 do 0NA NA NA A NA 1 Zn0=paste 0 NA NA NA NA NA 5 do G 0 NA NA NA NA At the5% level of adhesive additive, the sealant compositions were notcompletely cured.

Code: C =Cohesive failure; A=Adhesive failure; NA=No adhesion.

The data indicates that the sealant composition containing 1% adhesiveadditive and lead peroxide curing agent (Example 8) gave good adhesionto glass in both the air and water tests.

Adhesions of the above curable formulations were run in accordance withthe procedure described in Examples 8-11. Adhesion results are shown inTable V.

C onditlons 7 days in water Substrate additive Curingageut GlassAluminum Concrete Glass Aluminum Concrete TABLE V 7 days in air at roomtemp.

Example Percent number 1 PbO, peste A NA 5 do C 0 0 NA 0 C O NA NA NA 00 NA NA NA NA C 0 NA Some minor cure retardation noted at 5% level ofadditive in both 2110; and PhD: cured stocks.

Code: C =Cohesive failure; A=Adheslve failure; NA=N0 adhesion.

The above data shows that the epoxy terminated polysulfide adhesiveadditive at the 5% level gave excellent adhesion to glass and aluminumsubstrates in both the ZnO and PhD, cured sealants and in both air andwater adhesion tests.

Now having fully described my invention, I claim:

1. An abietate-modified polysulfide polymer prepared by reacting aliquid polythiol polymer having a molecular weight of 500 to 4000 andabietic acid in a solvent at a temperature of 150 C. to 200 C. under aninert atmosphere.

2. The abietate-modified polysulfide polymer as in claim 1 wherein theliquid polythiol polymer is a non-crosslinked liquid polythiol polymerhaving a molecular weight of References Cited UNITED STATES PATENTSDONALD E. CZAIA, Primary Examiner M. I. MARQUIS, Assistant Examiner US.Cl. X.R.

117-l24 E, 133; 26024, 31.2 R, 33.8 R, 37 R, S,

